Central venous catheters are widely used in the medical field. Some current drugs are caustic or irritating to lower arm veins which have smaller diameters. The standard of choice now is to deliver medications into larger blood vessels located in the central portion of the patient's chest. Thus, a catheter is advanced into the largest vein in the body, called the superior vena cava. Central lines are precisely placed at the junction of the superior vena cava and the heart's atrium.
In particular, a peripherally inserted central venous catheter (PICC or PICC line) is initially inserted into a peripheral vein, normally in the upper arm of the patient. It is then advanced through larger veins towards the heart for a prescribed distance. PICCs are intended to remain in place for extended periods, e.g. from a few days up to a few years. They provide a means for long-term chemotherapy regimens, extended antibiotic therapy, total parenteral nutrition, extended venous access, and blood sampling.
It is most important that a catheter tip, where introduced fluids exit the PICC and enter the body, be precisely positioned in the body. The catheter's tip must be positioned in the lower one-third of the superior vena cava, close to a junction of the superior vena cava and the heart's right atrium. Ultrasound, chest radiographs, and fluoroscopy techniques are used by trained nurses or doctors to aid in insertion of the catheter and to confirm that its tip is properly positioned. There are only a few centimeters of space in the superior vena cava vessel where it can safely sit. This is well accepted and is attainable provided proper care is taken by trained personnel, including a specially trained PICC nurse who first performs the procedure and a radiologist who confirms the position of the catheter's tip. The initial positioning of the catheter tip is critical, but follow-up monitoring is just as important.
The PICC must remain in its exact place once properly positioned or at least be readily repositioned if need be. Any catheter tip movement can lead to an enormous increase, e.g. 60% to 70% in the rate of thrombosis, infection, heart dysrythmias and perforation, or catheter dysfunction. Simply taping the catheter to the patient at its entry point into the body is not permissible because of the increased risk of infection at the site. Because a catheter's length inside the patient's body is a specific fit to their unique vasculature, all measurements are different. Generally, there are several centimeters of catheter left outside the upper arm, configured in an upward loop to avoid the bend in one's arm. This loop of catheter, in turn, leaves a degree of “play” or instability related to its original position. The catheter exits the vein through a tiny cut in the arm and is held in place only by a sticky clear occlusive sterile dressing. Close monitoring and meticulous care are required to ensure the catheter does not move. Catheter tip movement can be caused by several factors. A patient's natural body movements is one cause. Perspiration, moisture or blood under the dressing, all of which loosen the dressing's adhesive, is another cause. Strenuous physical activity of the upper extremities and poor technique during dressing changes are some other examples. Considering a patient may be required to keep a PICC line in place continually for weeks and even months at a time, it should not be surprising that inadvertent movements and bumpings that affect the catheter's tip placement will occur. Further, multiple dressing changes by different clinicians, possibly at different hospital units and other medical facilities all present opportunities for the initial precise positioning of the catheter tip to be totally negated.
There often is no continuity in the maintenance of the PICC's original position because no visual cue exists. With the plethora of activity surrounding a patient and the unfortunate fact that hospitals do not use “position indicators” or any type of label to aid in monitoring catheters (even those residing near one's heart) the safety of PICC lines are diminished. It is a simple fact the catheter tip frequently moves and the movement goes undetected. Poor catheter management leads to unwanted chemical and mechanical irritation of a vessel which triggers the clotting process leading to thrombosis and catheter-related infections.
Another potential problem with PICC's is the fact it is known that the catheter line can sometimes simply break off while in the patient's body. It is imperative that when a PICC procedure is completed and the catheter line retracted that the full length be retracted. Any broken-off portion which remains behind can ultimately cause severe damage to the patient. There is currently not a measure in place which ensures that no portion of the catheter line has been left behind. Referring to the original medical chart would help, but the chart is often unavailable to the clinician.
The lengths of catheter within the body and outside the body when a PICC procedure is first performed is recorded on the patient's medical chart. Regardless, the information is of little value when there are frequent follow-up facilities involved and many different medical personnel that can be involved over a course of possibly months. All the while clotting formation, infection, and catheter dysfunction in the patient due to catheter movement is possible.
There are no indicators to compare the present location of the tip of the catheter in the vessel with its original safe position within the vein. Simply looking at the exterior portion of a PICC is of no avail to determining if it has moved further into or out of the patient's body. Basically, clinicians today employ guesswork when maintaining these lines. This places an individual at great risk, sometimes even life threatening.
What is needed is an improved PICC which allows trained medical personnel to detect movement and immediately know if corrective action is needed. In response to this need, there has now been developed a position indicator designed specifically for use with central venous catheters and a method of monitoring safe use of the central venous catheter. It is especially for use with PICCs. This is because PICCs are placed in a patient's arm where a lot of movement takes place with a consequent enhanced chance for catheter movement.